/*
 * Copyright (c) 2020 Uber Technologies, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *     http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.uber.rss.metrics;

import java.util.concurrent.ConcurrentHashMap;
import java.util.function.Function;

public class MetricGroupContainer <K, M extends MetricGroup<K>> {
    private final Function<? super K, ? extends M> createFunction;
    
    private final ConcurrentHashMap<K, M> metricGroups = new ConcurrentHashMap<>();

    public MetricGroupContainer(Function<? super K, ? extends M> createFunction) {
        this.createFunction = createFunction;
    }

    public M getMetricGroup(K key) {
        return metricGroups.computeIfAbsent(key, createFunction);
    }

    public void removeMetricGroup(K key) {
        M metricGroup = metricGroups.remove(key);
        if (metricGroup != null) {
            metricGroup.close();
        }
    }
}
